Electrodes are used in a wide variety of medical applications. For example, electrodes are used with external defibrillators, to deliver a defibrillating shock to a patient.
Typically, two separate electrodes are applied to the patient for defibrillation treatments. In order for the defibrillating shock to be effective, it is important that the electrodes be positioned so that current flowing from one electrode to the other passes along a straight line that intersects or passes close to the patient's heart (ideally through the ventricles). It is also necessary that good skin contact be made between the electrodes and the patient's skin.
It may be difficult for lay or even skilled caregivers to position the electrodes correctly during emergency treatment. It may also be difficult to get good skin contact, particularly if the electrodes do not conform well to the body contours of the patient. Delay in correct positioning of defibrillator electrodes can mean the difference between life and death to a victim of cardiac arrest.